856688040 has 144 divisors (see below), whose sum is σ = 3015097020. Its totient is φ = 210862080.

The previous prime is 856688039. The next prime is 856688099. The reversal of 856688040 is 40886658.

856688040 is a `hidden beast` number, since 8 + 566 + 8 + 80 + 4 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 199996164 + 656691876 = 14142^2 + 25626^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 53800 + ... + 67880.

Almost surely, 2^856688040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 856688040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1507548510).

856688040 is an abundant number, since it is smaller than the sum of its proper divisors (2158408980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856688040 is a wasteful number, since it uses less digits than its factorization.

856688040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14124 (or 14104 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The square root of 856688040 is about 29269.2336763367. The cubic root of 856688040 is about 949.7462073669.

The spelling of 856688040 in words is "eight hundred fifty-six million, six hundred eighty-eight thousand, forty".